This project represents an ongoing collaborative effort, involving WHO and other national and international laboratories to coordinate the collection, evaluation and interpretation of normal genetic markers in order to study the cross-cultural patterns of genetic and extraneous factors as they relate to normative aging and to diseases with late onset, including Alzheimer's disease, breast cancer, Amyotrophic Lateral Sclerosis, and Parkinsonism Dementia. Specifically, the objectives of this study are: A) To study the cross cultural patterns of genetic and non-genetic 1 factors in an effort to better understand the process of normative aging. B) To study the genetic segregation of these markers in families with late onset diseases, such as Alzheimer's disease, breast cancer, ALS and others, in an effort to establish genetic linkages and eventual identification of the factors responsible, for these diseases. C) To study the distribution of dermatoglyphics, lateral dominance and other genetic variables in BLSA participants and other control samples, as well as in patients with late onset diseases.